Diazobenzenes

Dissolve the substance in a few c.c. of cold water and add a solution of bromine in potassium bromide until no fartlier turbidity is produced. A black oil collects at the bottom of the test-tube. Pour off the top layer as far as possible, and let the oil stand in cold water. It solidifies. This is the perbromicle of diazobenzene. 

Diazobenzene Sulphate.—Whereas nitrous acid immediately decomposes the primary aliphatic amines wdth et olution of nitiogen,... 

The hydrate of diazobenzene, C H No.OH, which would be analogous to NH4OH, is also known as an unstable oil. Con-... 

If nitrous acid is added, the second molecule of base is also comerted into diazobenzene chloiide. In presence of cuprous chloiide, chlorobenzene is formed. 

It should be noted that the action of phenylhydrazine on the ketone group, and of diazobenzene salts on the methylene group situated between two CO groups, are analogous to that of hydrovylaniine and nitrous acid upon these two groups, of which the following are examples —... 

Diazo-benzol, n. diazobenzene, -essigsaure,/. diazoacetic acid, -kdrper, m. diazo compound. -Idsung, /. diazo solution, -salz, n. diazo salt (usually a diazonium salt), -schwarz, n, diazo black, diazotierbar, a. diazotizable. diazotieren, v.t. diazotize. 

Kinetic isotope effects have not been observed in the reaction of 1-naphthol-4-sulphonic-2-acid with 2-methoxydiazobenzene127, imidazole-2,4,5-d3 with 4-diazobenzene sulphonic acid128, or indole-3- / with 4-nitrodiazobenzene12S, nor has base catalysis been observed in those cases where it has been measured in each of these reactions one or both of the reagents is relatively reactive. 

Only few applications have been reported to determine antioxidants in rubbers or polymers by using electrochemical methods [927,928]. Sawada et al. [929] reported successful separations by coupling the antioxidants with p-diazobenzene sulfonic acid before electrophoresis. Amine AOs were coupled in acetic acid and phenolic AOs in NaOH-ethanol were analysed by CE methods. MEKC separation of the four major food grade antioxidants (PG, BHA, BHT, TBHQ) was completed within 6 min with pmole amount detection using UV absorption [930]. RPLC was not as efficient and required larger sample amounts and longer separation times. 

The data below have been reported for the decomposition of diazobenzene chloride. 

The initial concentration of diazobenzene chloride was 5.0 kg/m3. The reaction is believed to be first order and irreversible. Determine if the reaction is indeed first order and evaluate the reaction rate constant. 

All primary nitro-compounds couple with diazobenzene, but instead of the expected azo-compounds, phenylhydrazones of a-nitro-aldehydes are formed by rearrangement of the molecule ... 

The method of reaction of the diazobenzene hydroxide is extraordinarily similar to that of nitrous acid practically all substances which are capable of coupling also react with this acid. Comparison of the formulae shows that in the diazo-hydroxide the bivalent radicle... 

Accordingly, diazobenzene and nitrous acid are related to each other in the same way as are phenylhydrazine and hydroxylamine the latter two substances, in fact, yield the same reaction products with carbonyl compounds as the former two do with the corresponding methylene derivatives. 

It is consequently intelligible that certain quinones condense with phenylhydrazine to the same end products as are formed by the coupling of the corresponding phenols with diazobenzene hydroxide (Zincke), e g.,... 

The tertiary aromatic bases share with the phenols the property of taking up a nitroso-group in the p-position when treated with nitrous acid in acid solution. As was mentioned elsewhere (p. 307), this reaction may be compared to the coupling of these compounds with diazobenzene. 

G. Qros, T. Cserhati and E. Forgacs, Separation of the strength and selectivity of the microbiological effect of synthetic dyes by spectral mapping technique. Chemosphere, 52 (2003) 185-193. G. Oros, T. Cserhati and E. Forgacs, Strength and selectivity of the fungicidal effect of diazobenzene dyes. Fres. Env. Bull., 10 (2001) 319-322. 

Berthelot and Vieille [1] examined the explosive properties of diazobenzene nitrate (C6H5N = N) NOf. Later Wohler and Matter [2] demonstrated that it is unsuitable for use as an initiator due to its very weak initiating properties and very high sensitiveness to friction and impact. Herz [3] suggested the use of m-nitrodiazobenzene perchlorate. This, however, is hygroscopic and insufficiently stable (it explodes at 154°C). 

Diazobenzene Sulfocyanate or Di azobenzene Th iocyanate. See Benzenediazonium Sulfocyanate in Vo 2, p B57-L... 

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